The Mercedes-Benz GLK is a likeable and sturdy small crossover with family function amid upscale accommodations that are not too precious to get dirty.

It has been sold in two V-6 models in rear- or all-wheel drive with starting prices of $37,995 and $39,995. But the big news this year is the new, four-cylinder diesel model, the GLK250 Bluetec, today’s test car.

It starts at a reasonable $39,495 with AWD (which Mercedes calls 4Matic). The test vehicle – $57,635 – was a showcase of available options for advanced technologies – parking assist and active lane-keeping assist among them – and premium extras, such as full leather ($1,200), which is nice but not a necessity when the standard M-B Tex leatherette is a good simulation.

The option for full leather ($1,200) is quality, but not a necessity when the standard M-B Tex leatherette is a good simulation.

The gear selector is on the steering column, which opens the floor console for more open storage and device-charging space.

Priced between the V-6 models, the Bluetec trumps with fuel economy of 24 mpg city, 33 highway and 28 combined. In my test week, the combined mileage averaged 30 to 33.7 mpg and I wasn’t trying to conserve. The gasoline V6 4Matic is rated 19/24/21 mpg on premium fuel.

Even better is the driving range. The 17.4-gallon tank puts at least 500 miles between fill-ups, which makes the GLK Bluetec a credible commuter.

The ride quality is settled and soft on the Interstate, but firm shock absorbers and stabilizer bars give control in evasive maneuvers.

Driver and passenger have command seating with open sightlines over the fenders and over the shoulder. The gear selector is on the steering column, which opens the floor console for more open storage and device-charging space.

There’s also some of that Mercedes-Benz vault-like solidity in the soundproofed cabin. There’s only some wind noise at higher speeds, due mostly to the upright windshield and possibly the roof rails.

The back seat has a fairly narrow door opening for adult entry and exit, but there is good footroom and 35 inches of legroom. The center position is squeezed by a tall transmission tunnel and narrow seat. But there is a good fold-down armrest with cup holders for those at the window seats to enjoy.

The cargo area is large and square, which expands capacity from 23.3 cubic feet to 54.7 with the flat-folding back seat. There is 37 inches between the wheel housings and enough length to slide in 5-foot boards, bikes, gear. Aluminum roof rails are part of the $990 Appearance package, which includes five-spoke 19-inch alloy wheels. Brushed aluminum runningboards with rubber studs ($670) give a toehold for stepping up to strap down a bicycle, but they also stick out far enough to complicate entry and entry, dirtying a pant leg in the process.

There is little to giveaway this model as a diesel; even the badging identifies it as Bluetec. The direct-injection engine reduces the traditional diesel clatter to a purring tappet sound at idle. There is no smoke and no exhaust smell unless you sniff the tailpipe.

The engine service is more expensive than for a gasoline model, Mercedes-Benz says, but the long-term savings in fuel costs make the additional service cost a non-issue.

The AdBlue tank, under the cargo-area, will be refilled at the scheduled maintenance intervals, 12-months or 10,000 miles.

To meet exhaust emission regulations in all 50 states, a water-based urea solution, AdBlue, is spritzed into the exhaust. This form of exhaust gas after-treatment causes ammonia to be released, which converts nitrogen oxides into (harmless) nitrogen (and water) in a catalytic converter. The AdBlue tank will be refilled at the scheduled maintenance intervals, 12-months or 10,000 miles. The service is more expensive than for a gasoline model, Mercedes-Benz says, but the long-term savings in fuel costs make the additional service cost a non-issue.